The side-scattering properties of the waveguide memory have been investigated by experiments in this paper. The results indicate that the side-scattering intensity decays exponentially along the propagating direction of the guide light. The attenuation constant is in proportion to the density of the scattering dots,and also increased with the laser beam energy that records the information dots. These experimental results contribute to optimize the density and size of the information dots, which leads to better scattering distribution of the information dots on the waveguide surface. Better sensitivity of the readout system of the memory, more SNR and higher utilizing efficiency of the laser energy can also be achieved by these optimizations.